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<title>Hash Random Int Find Timing Test</title>
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<h1>Hash-Based Random-Integer <tt>find</tt> Find Timing
    Test</h1>
<h2><a name="description" id="description">Description</a></h2>
<p>This test inserts a number of values with uniform i.i.d.
    integer keys into a container, then performs a series of finds
    using <tt>find</tt>. It measures the average time
    for<tt>find</tt> as a function of the number of values
    inserted.</p>
<p>(The test was executed with <a href="../../../../testsuite/performance/ext/pb_ds/random_int_find_timing.cc"><tt>random_int_find_timing_test</tt></a>
    200 200 2100)</p>
<h2><a name="purpose" id="purpose">Purpose</a></h2>
<p>The test checks the effect of different underlying
    hash-tables (see <a href="hash_based_containers.html">Design::Associative
    Containers::Associative Containers::Hash-Based Containers</a>),
    range-hashing functions, and trigger policies (see <a href="hash_based_containers.html#hash_policies">Design::Associative
    Containers::Hash-Based Containers::Hash Policies</a> and
    <a href="hash_based_containers.html#resize_policies">Design::Associative
    Containers::Hash-Based Containers::Resize Policies</a>).</p>
<h2><a name="results" id="results">Results</a></h2>
<p>Figures <a href="#NCCG">NCCG</a>, <a href="#NCCM">NCCM</a>,
    and <a href="#NCCL">NCCL</a> show the results for the native
    and collision-chaining types in <a href="assoc_performance_tests.html#gcc"><u>g++</u></a>, <a href="assoc_performance_tests.html#msvc"><u>MSVC++</u></a>, and
    <a href="assoc_performance_tests.html#local"><u>local</u></a>,
    respectively; Figures <a href="#NGPG">NGPG</a>, <a href="#NGPM">NGPM</a>, and <a href="#NGPL">NGPL</a> show the results
    for the native and probing types in <a href="assoc_performance_tests.html#gcc"><u>g++</u></a>, <a href="assoc_performance_tests.html#msvc"><u>MSVC++</u></a>, and
    <a href="assoc_performance_tests.html#local"><u>local</u></a>
    respectively.</p>
<div id="NCCG_res_div">
<div id="NCCG_gcc">
<div id="NCCG_cc_hash_random_int_find_timing_test">
<div id="NCCG_assoc">
<div id="NCCG_Native_and_collision-chaining_hash_random_int_find_timing_test_using__tt_find_455tt_"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NCCG" id="NCCG"><img src="cc_hash_random_int_find_timing_test_gcc.png" alt="no image" /></a></h6>NCCG: Native and collision-chaining hash random int find timing test using <tt>find</tt> - <a href="assoc_performance_tests.html#gcc">g++</a><p>In the above figure, the names in the legends have the following meaning:</p>
<ol>
<li>
n_hash_map_ncah-
<tt>std::tr1::unordered_map</tt> with <tt>cache_hash_code</tt> = <tt><b>false</b></tt></li>
<li>
cc_hash_mod_prime_nea_lc_1div8_1div1_nsth_map-
<a href="cc_hash_table.html"><tt>cc_hash_table</tt></a>
with <tt>Comb_Hash_Fn</tt> = <a href="direct_mod_range_hashing.html"><tt>direct_mod_range_hashing</tt></a>
, and <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_prime_size_policy.html"><tt>hash_prime_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/1</i></li>
<li>
cc_hash_mod_prime_nea_lc_1div8_1div2_nsth_map-
<a href="cc_hash_table.html"><tt>cc_hash_table</tt></a>
with <tt>Comb_Hash_Fn</tt> = <a href="direct_mod_range_hashing.html"><tt>direct_mod_range_hashing</tt></a>
, and <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_prime_size_policy.html"><tt>hash_prime_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/2</i></li>
<li>
cc_hash_mask_exp_nea_lc_1div8_1div1_nsth_map-
<a href="cc_hash_table.html"><tt>cc_hash_table</tt></a>
with <tt>Comb_Hash_Fn</tt> = <a href="direct_mask_range_hashing.html"><tt>direct_mask_range_hashing</tt></a>
, and <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_exponential_size_policy.html"><tt>hash_exponential_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/1</i></li>
<li>
cc_hash_mask_exp_nea_lc_1div8_1div2_nsth_map-
<a href="cc_hash_table.html"><tt>cc_hash_table</tt></a>
with <tt>Comb_Hash_Fn</tt> = <a href="direct_mask_range_hashing.html"><tt>direct_mask_range_hashing</tt></a>
, and <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_exponential_size_policy.html"><tt>hash_exponential_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/2</i></li>
</ol>
</div><div style="width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NCCM_res_div">
<div id="NCCM_msvc">
<div id="NCCM_cc_hash_random_int_find_timing_test">
<div id="NCCM_assoc">
<div id="NCCM_Native_and_collision-chaining_hash_random_int_find_timing_test_using__tt_find_455tt_"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NCCM" id="NCCM"><img src="cc_hash_random_int_find_timing_test_msvc.png" alt="no image" /></a></h6>NCCM: Native and collision-chaining hash random int find timing test using <tt>find</tt> - <a href="assoc_performance_tests.html#msvc">msvc++</a><p>In the above figure, the names in the legends have the following meaning:</p>
<ol>
<li>
cc_hash_mod_prime_nea_lc_1div8_1div1_nsth_map-
<a href="cc_hash_table.html"><tt>cc_hash_table</tt></a>
with <tt>Comb_Hash_Fn</tt> = <a href="direct_mod_range_hashing.html"><tt>direct_mod_range_hashing</tt></a>
, and <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_prime_size_policy.html"><tt>hash_prime_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/1</i></li>
<li>
cc_hash_mod_prime_nea_lc_1div8_1div2_nsth_map-
<a href="cc_hash_table.html"><tt>cc_hash_table</tt></a>
with <tt>Comb_Hash_Fn</tt> = <a href="direct_mod_range_hashing.html"><tt>direct_mod_range_hashing</tt></a>
, and <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_prime_size_policy.html"><tt>hash_prime_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/2</i></li>
<li>
n_hash_map_ncah-
<tt>stdext::hash_map</tt></li>
<li>
cc_hash_mask_exp_nea_lc_1div8_1div1_nsth_map-
<a href="cc_hash_table.html"><tt>cc_hash_table</tt></a>
with <tt>Comb_Hash_Fn</tt> = <a href="direct_mask_range_hashing.html"><tt>direct_mask_range_hashing</tt></a>
, and <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_exponential_size_policy.html"><tt>hash_exponential_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/1</i></li>
<li>
cc_hash_mask_exp_nea_lc_1div8_1div2_nsth_map-
<a href="cc_hash_table.html"><tt>cc_hash_table</tt></a>
with <tt>Comb_Hash_Fn</tt> = <a href="direct_mask_range_hashing.html"><tt>direct_mask_range_hashing</tt></a>
, and <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_exponential_size_policy.html"><tt>hash_exponential_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/2</i></li>
</ol>
</div><div style="width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NCCL_res_div">
<div id="NCCL_local">
<div id="NCCL_cc_hash_random_int_find_timing_test">
<div id="NCCL_assoc">
<div id="NCCL_Native_and_collision-chaining_hash_random_int_find_timing_test_using__tt_find_455tt_"><div style = "border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NCCL" id= "NCCL"><img src="cc_hash_random_int_find_timing_test_local.png" alt="no image" /></a></h6>NCCL: Native and collision-chaining hash random int find timing test using <tt>find</tt> - <a href = "assoc_performance_tests.html#local">local</a></div><div style = "width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NGPG_res_div">
<div id="NGPG_gcc">
<div id="NGPG_gp_hash_random_int_find_timing_test">
<div id="NGPG_assoc">
<div id="NGPG_Native_and_collision-chaining_hash_random_int_find_timing_test_using__tt_find_455tt_"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NGPG" id="NGPG"><img src="gp_hash_random_int_find_timing_test_gcc.png" alt="no image" /></a></h6>NGPG: Native and collision-chaining hash random int find timing test using <tt>find</tt> - <a href="assoc_performance_tests.html#gcc">g++</a><p>In the above figure, the names in the legends have the following meaning:</p>
<ol>
<li>
gp_hash_mod_quadp_prime_nea_lc_1div8_1div2_nsth_map-
<a href="gp_hash_table.html"><tt>gp_hash_table</tt></a>
 with <tt>Comb_Hash_Fn</tt> = <a href="direct_mod_range_hashing.html"><tt>direct_mod_range_hashing</tt></a>
, <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_prime_size_policy.html"><tt>hash_prime_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/2</i>, and <tt>Probe_Fn</tt> = <a href="quadratic_probe_fn.html"><tt>quadratic_probe_fn</tt></a>
</li>
<li>
n_hash_map_ncah-
<tt>std::tr1::unordered_map</tt> with <tt>cache_hash_code</tt> = <tt><b>false</b></tt></li>
<li>
gp_hash_mask_linp_exp_nea_lc_1div8_1div2_nsth_map-
<a href="gp_hash_table.html"><tt>gp_hash_table</tt></a>
 with <tt>Comb_Hash_Fn</tt> = <a href="direct_mask_range_hashing.html"><tt>direct_mask_range_hashing</tt></a>
, <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_exponential_size_policy.html"><tt>hash_exponential_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/2</i>, and <tt>Probe_Fn</tt> = <a href="linear_probe_fn.html"><tt>linear_probe_fn</tt></a>
</li>
</ol>
</div><div style="width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NGPM_res_div">
<div id="NGPM_msvc">
<div id="NGPM_gp_hash_random_int_find_timing_test">
<div id="NGPM_assoc">
<div id="NGPM_Native_and_collision-chaining_hash_random_int_find_timing_test_using__tt_find_455tt_"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NGPM" id="NGPM"><img src="gp_hash_random_int_find_timing_test_msvc.png" alt="no image" /></a></h6>NGPM: Native and collision-chaining hash random int find timing test using <tt>find</tt> - <a href="assoc_performance_tests.html#msvc">msvc++</a><p>In the above figure, the names in the legends have the following meaning:</p>
<ol>
<li>
gp_hash_mod_quadp_prime_nea_lc_1div8_1div2_nsth_map-
<a href="gp_hash_table.html"><tt>gp_hash_table</tt></a>
 with <tt>Comb_Hash_Fn</tt> = <a href="direct_mod_range_hashing.html"><tt>direct_mod_range_hashing</tt></a>
, <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_prime_size_policy.html"><tt>hash_prime_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/2</i>, and <tt>Probe_Fn</tt> = <a href="quadratic_probe_fn.html"><tt>quadratic_probe_fn</tt></a>
</li>
<li>
n_hash_map_ncah-
<tt>stdext::hash_map</tt></li>
<li>
gp_hash_mask_linp_exp_nea_lc_1div8_1div2_nsth_map-
<a href="gp_hash_table.html"><tt>gp_hash_table</tt></a>
 with <tt>Comb_Hash_Fn</tt> = <a href="direct_mask_range_hashing.html"><tt>direct_mask_range_hashing</tt></a>
, <tt>Resize_Policy</tt> = <a href="hash_standard_resize_policy.html"><tt>hash_standard_resize_policy</tt></a>
 with <tt>Size_Policy</tt> = <a href="hash_exponential_size_policy.html"><tt>hash_exponential_size_policy</tt></a>
, and <tt>Trigger_Policy</tt> = <a href="hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger</tt></a>
 with <i>&alpha;<sub>min</sub></i> = <i>1/8</i> and <i>&alpha;<sub>max</sub></i> = <i>1/2</i>, and <tt>Probe_Fn</tt> = <a href="linear_probe_fn.html"><tt>linear_probe_fn</tt></a>
</li>
</ol>
</div><div style="width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NGPL_res_div">
<div id="NGPL_local">
<div id="NGPL_gp_hash_random_int_find_timing_test">
<div id="NGPL_assoc">
<div id="NGPL_Native_and_collision-chaining_hash_random_int_find_timing_test_using__tt_find_455tt_"><div style = "border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NGPL" id= "NGPL"><img src="gp_hash_random_int_find_timing_test_local.png" alt="no image" /></a></h6>NGPL: Native and collision-chaining hash random int find timing test using <tt>find</tt> - <a href = "assoc_performance_tests.html#local">local</a></div><div style = "width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<h2><a name="observations" id="observations">Observations</a></h2>
<p>In this setting, the choice of underlying hash-table (see
    <a href="hash_based_containers.html">Design::Associative
    Containers::Hash-Based Containers</a> ) affects performance
    most, then the range-hashing scheme (See <a href="hash_based_containers.html#hash_policies">Design::Associative
    Containers::Hash-Based Containers::Hash Policies</a> ), and,
    only finally, other policies.</p>
<p>When comparing Figures <a href="#NCCG">NCCG</a> and <a href="#NCCM">NCCM</a> to <a href="#NGPG">NGPG</a> and <a href="#NGPM">NGPM</a> , respectively, it is apparent that the
    probing containers are less efficient than the
    collision-chaining containers (both
    <tt>std::tr1::unordered_map</tt> and <tt>stdext::hash_map</tt>
    use collision-chaining) in this case.</p>
<p>( <a href="hash_random_int_subscript_insert_timing_test.html">Hash-Based
    Random-Integer Subscript Insert Timing Test</a> shows a
    different case, where the situation is reversed; <a href="assoc_performance_tests.html#hash_based_types">Observations::Hash-Based
    Container Types</a> discusses some further considerations.)</p>
<p>Within each type of hash-table, the range-hashing scheme
    affects performance more than other policies; <a href="hash_text_find_find_timing_test.html#observations">Hash-Based
    Text <tt>find</tt> Find Timing Test::Observations</a> discusses
    this. In Figures <a href="#NCCG">NCCG</a> , <a href="#NCCM">NCCM</a> , <a href="#NGPG">NGPG</a> , and <a href="#NGPM">NGPM</a> , it should be noted that
    <tt>std::tr1::unordered_map</tt> and <tt>stdext::hash_map</tt>
    are hard-wired currently to mod-based and mask-based schemes,
    respectively.</p>
<p><a href="assoc_performance_tests.html#hash_based_types">Observations::Hash-Based
    Container Types</a> summarizes some observations on hash-based
    containers; <a href="assoc_performance_tests.html#hash_based_policies">Observations::Hash-Based
    Containers' Policies</a> summarizes some observations on
    hash-based containers' policies.</p>
</div>
</body>
</html>
